Add constructors to all the event classes.

client/html/src/PopStateEventWrappingImplementation.dart

Index: client/html/src/PopStateEventWrappingImplementation.dart
diff --git a/client/html/generated/src/wrapping/_PopStateEventWrappingImplementation.dart b/client/html/src/PopStateEventWrappingImplementation.dart
similarity index 54%
rename from client/html/generated/src/wrapping/_PopStateEventWrappingImplementation.dart
rename to client/html/src/PopStateEventWrappingImplementation.dart
index f9ed5253d841b7d1461c10df36de6567cfcbf3d8..bd2f021f4f21caac446ca4d7cf04f041236826ed 100644
--- a/client/html/generated/src/wrapping/_PopStateEventWrappingImplementation.dart
+++ b/client/html/src/PopStateEventWrappingImplementation.dart
@@ -2,15 +2,15 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-// WARNING: Do not edit - generated code.
-
 class PopStateEventWrappingImplementation extends EventWrappingImplementation implements PopStateEvent {
-  PopStateEventWrappingImplementation._wrap(ptr) : super._wrap(ptr) {}
-
-  String get state() { return _ptr.state; }
+  PopStateEventWrappingImplementation._wrap(ptr) : super._wrap(ptr);
 
-  void initPopStateEvent(String typeArg, bool canBubbleArg, bool cancelableArg, Object stateArg) {
-    _ptr.initPopStateEvent(typeArg, canBubbleArg, cancelableArg, LevelDom.unwrapMaybePrimitive(stateArg));
-    return;
+  factory PopStateEventWrappingImplementation(String type, Object state,
+      [bool canBubble = true, bool cancelable = true]) {
+    final e = dom.document.createEvent("PopStateEvent");
+    e.initPopStateEvent(type, canBubble, cancelable, state);
+    return LevelDom.wrapPopStateEvent(e);
   }
+
+  String get state() => _ptr.state;
 }